System for feeding and transporting materials



July 27, 1965 J. 1-1. KAUFFMAN 3,197,260

. SYSTEM FOR FEEDING AND TRANSPORTING MATERIALS Filed Sept. 26, 1962 5 Sheets-Sheet 1 FIG. 2

IN VENTOR L/Of/A/ H. KAUFFMAN BY 7/440, 5m,

ATTORNEYS July 27, 1965 J. H. KAUFFMAN 3,197,260

SYSTEM FUR FEEDING AND TRANSPORTING MATERIALS Filed Sept. 26, 1962 5 Sheets-Sheet 5 INVENTOR lob/Al H. KAUFFM 5 QZlw... f I

ATTORNEYS y 1965 J. H. KAUFFMAN 3,197,260

SYSTEM FOR FEEDING AND TRANSPORTING MATERIALS Filed Sept. 26, 1962 5 Sheets-Sheet 4 224 INVENTOR Job Al H KAuI-"FMAM 5 BY MM F 7 MM; (0744.

ATTORNEYS July 27, 1965 J. H. KAUFFMAN 3,197,260

SYSTEM FOR FEEDING AND TRANSPORTING' MATERIALS Filed Sept. 26, 1962 5 Sheets-Sheet 5 INVENTOR. JOHN H. KAUFFMAN BYZMQM,

07M 20% f? %M ATTORNEYS United States Patent A 3,197,260 SYSTEM FOR FEEDING AND TRANSPGRTING MATERIALS John H. Kaufiman, -Crystal Lake, 111., assiwor to Herbert Simpson 'Corporation, Chicago, 11]., a corporation of Illinois Filed Sept. 26, 1962, Ser. No. 226,339 11 Claims. (Cl. 3l)2'55) This invention relates to a system for feeding and transporting materials and is more particularly concerned with a system for feeding materials at a metered flow rate and transporting the materials thus metered to various locations.

An object of the present invention is to provide a new and improved system for feeding and transporting materials which is simple and economical in operation and construction, and one which will readily handle a variety of difierent materials Another object of the invention is to provide a new and improved system for feeding and transporting materials in which the materials are fed and transported at a metered rate which is easily adjustable to handle a variety of diflerent materials at a variety of different metering rates.

-Another object of thelinvention is to provide a new and improved system for feeding and transporting materials in which abrasive materials, such as sand, grit and the like, can be handled with a minimum of wear and abrasion on the system.

Another object of the invention is to provide a new and improved system for feeding and transporting materials in which solid materials are fed at a metered rate into a fluid flow for trausportationto various locations.

Another object of the invention is to provide a new and improved system for feeding and transporting materials in which solid materials are fed at a mete-red rate which is relatively constant and in which the materials being fed are prevented from bridging or building up and causing the flow to stop or the rate to change a substantial amount.

Another object of the invention is to provide a new and improved system for feeding and transporting materials in which solid materials, such as sand, grit, powder and the like, are fed at a metered rate into a pneumatic transport duct having a pressure different from the feed hopper containing the materials.

Another object of the invention is to provide a new and improved feeder which can be utilized to feed materials into or out of a pneumatic transport duct from an area of low to relatively high pressure or vice versa while maintaining a relatively constant rate of flow for a variety of materials and a variety of different flow rates.

The foregoing and other objects of the present invention are accomplished by providing a system for feeding and transporting materials including a flow duct having a fluid flow therethrough. A hopper is provided for conrtaining the materials to be fed and transported, and'this hopper is connected to the flow duct through a valve chamber. The chamber is provided with a pair of opposed valve seats and a valve member is reciprocally mounted in the chamber which moves to alternately seat against first one valve seat and then the other. Means are provided to reciprocate the valve means to accomplish this alternate seating to allow the material to flow from the hopper into the chamber when the valve member is seated against one seat and then from the chamber into the flow duct when the valve member is seated against the other seat.

According to another embodiment of the invent-ion, the valve chamber is provided with three seats and a valve member is movably mounted therein to alternately seat first against one seat allowing material to flow from i the hopper into one portion of the chamber and from another portion of the chamber into the flow duct and then against the other two seats for allowing the material to flow from one portion of the chamber to the other portion thereof.

A further embodiment of the invention comprises a valve chamber having four seats which define three sub chambers with a valve member movably mounted therein to alternately seat first against two of the seats to allow material to flow from the hopper into the first subchambet and the material in the first subchamber to flow from the second subch'amber into the third and then to seat against the other two seats to allow material to flow from the first subchamber' into the second and material in the third subchamber to flow into the flow duct.

In yet another embodiment, a valve chamber is provided with four seats which define three subchambers and contain a pair of individually controlled movably mounted valve members. One valve member is independently controllable to alternately seat first against a first seat to allow material to flow into a first subchamber from the hopper and then to seat against a second seat to allow material to flow from the first .subchamber into a second subchamber. The other valve member is independently controllable to alternately seat first against the third seat to allow material to flow from the second subchamber into a third subchamber and then to seat against a fourth seat to allow the material to flow from the third subcharnber into the flow duct.

The speed of reciprocation as well as the time duration that the valve member is seated on either seat of the feeder mechanisms described above can be easily and automatically controlled and adjusted to regulate the flow of a variety of different materials under a variety of different operating conditions.

Other objects and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the drawings in which: i

FIG, 1 is a sectional, elevational View of a material feeding and transporting device as characterized by the features of the present invention with the sectional portions taken substantially along line 1-1 of FIG. 2;

FIG. 2 is a sectional view taken substantially along line 2-2 of FIG. 1;

l lG. 3 is a schematic diagram of one embodiment of I a mechanism for reciprocating the valve disks of the material feeder of FIG. 1

FIG. 4- is a schematic diagram of another embodiment of a mechanism for reciprocating the valve disks of the material feeder of the present invention;

FIG. 5 is a sectional, elevational view of another embodiment of the present invention with the sectional portions taken substantially along line 5-5 of FIG. 6;

FIG. 6 is a sectional view taken substantially along line 6-6 of FIG. 5;

FIG. 7 is a sectional, elevational view of another embodiment of the present invention utilizing a triple valve means;

FIG. 8 is a sectional, elevational view of yet another embodiment of the present invention utilizing a quadruple valve means;

FIG. 9 is a sectional, elevational view of still another embodiment of the present invention utilizing two independently controlled valve members;

FIG. 10 is a sectional, elevational view of a feedingv Patented July 27, 1965 Referring now to the drawings and particularly FIGS. 1 and 2, there is illustrated one form of a material feeding and transporting system as characterized by the features of the present inventionand indicated generally by the reference numeral 2%. The material feeding system 29 includes a hopper 2?. for holding a quantity of material 24 which is to be fed and transported by the system; The hopper 22 is provided with a sloping bottom wall 26, a pair of sloping side walls 23 and a vertical front wall 3%. The walls may be joined together to form the hopper in a conventional manner such as welding or flange and bolt construction. If greater hopper capacity is desired for holding larger quantities of material, a large hopper 32 can be attached to the top of the hopper 22 in a conventional manner, such as by welding or bolts and flange construction.

Adjacent the center portion of the front wall 39 of the hopper 22, there is provided a generally rectangular feeding chamber 34-. The feeding chamber 34 is formed by the front wall 30 of the hopper 22, a pair of vertical side walls 36, a top wall 33, a bottom wall 49 and a front ertical wall 42. T he front wall 42. is comprised of an outer expanded metal screen 42a and an inner cotton filter or vent cloth 4212 which will pass air but retain the material ormay be of solid material such as clear plastic when the chamber 34 is either pressurized or evacuated as required in some types of systems. The front edges of the side walls 35, the top wall 38 and the bottom wall at) are provided with flanges to which the front wall 42?. is bolted by means of the bolts 44 so that the front wall can be easily removed for cleaning out the chamber when necessary. A gasket .6 is provided between the front wall 42 and the flange to effect a material tight seal therebetween. The front wall 3%) is provided with an opening or cutout 369a at t e bottom central portion thereof so that material in the hopper 24 will readily flow into the feedgrally formed with the wall 26 of the hopper 22 or attached thereto in a conventional manner, such as by welding. The bottom wall 40 of the feeding chamber 34 is provided with a feed opening 459a through which material fiows into a valve chamber 48. 7

There is also provided an internal baffle plate 41 which prevents the material from flowing directly from the opening in thewall 3% against the front wall 42 and thus allows air from the valve chamber 48 to flow freely up through the opening 40a in the bottom on the outer side of the baffle plate 41 to escape out the front wall 42 it so desired.

of the chamber 48, it is constructed of anupper member 52; and a lower member 54 which are provided with flanges and are held together by a plurality of bolts 56. A gasket 58 is provided between the flanges of the members 52 and 54 to provide a seal therebetween. The upper member 52 is joined to the vertical flange of the angle ring 5'9 by welding or other suitable means. The lower end of the valve chamber 43 is attached to a flow duct 56 so that material may be fed from the chamber into the duct through the opening 5%. Depending upon the relative diameters of the opening 53b and the duct 56, an opening of the proper size is cut into the duct and bottom plates 53 are provided so that an airtight connection between the inside of the chamber 48 and the inside of the duct 55 is obtained.

Within the chamber 48 there are provided a pair of coaxial, parallel aligned upper and lower valve disks 6t) and 62. The valve disks are positioned on an axially aligned threaded rod 64 so as to move together as a unit. The disks are constructed of resilient material such as hard rubber and are secured in position on the rod relative to each other by means of washers'and nuts on each side of the disks. When the rod 64 is in its upper position as shown in FIG. 2, the upper disk 60 is seated against th surface 4th: of the valve chamber and the lower disk s2 is spaced upwardly from the'lower seating surface Stla of the chamber. In this position, the chamber 46 is sealed The valve chamber 48 is attached to the bottom wall as in coaxial relation to the opening sea thereof by means of rolled angle ring 51 and a plurality of bolts 51a. A

gasket 53 is positioned between the horizontal flange of the angle ring 51 and the bottom wall 4 3 to provide a seal therebetween and to isolate the hopper and feeding chamber from some of the vibrations present in the valve chamher when the systemis in operation.

The valve chamber 43 is substantially cylindrical in its mid portion and is provided with inwardly converging walls at its upper end which provide a generally conical seating surface 33:? and terminate to form a feed opening 43b which is of smaller diameter than the cylindrical portion adjacent the middle of the chamber. The lower end of the chamber 48 is also provided. with inwardly con verging walls which provide a generally conical lower seating surface 56a and terminate to form a lower discharge opening Sill) which is smaller in diameter than the mid-cylindrical portion of the chamber.

For ease in construction and to facilitate the cleaning off from the feeding chamber 34 but is open to the duct 56. When the rod 64 is'in the lower position as shown in FIG. 1, the upper disk 6!! is below the seating surface 48:: of the chamber and the lower disk 62 is seated against the lower seating surface Stla of the chamber. In this position the chamber 48 is open to the feeding chamber 34 and is closed to the duct 56. The spacing of the valve disks 69 and 62 from each other can easily be changed from time to time to compensate for wear on the disks and seating surfaces and to adjust the travel. distance of the rod necessary to alternately seat the disks by loosening the nuts holding the disks on the rod. Similarly, the disks can also be rotated to compensate for uneven Wear on their peripheries.

When the disks are in the position shown in FIG. 1, material flows into the chamber 48 from the feeding compartment 34 but cannot flow from the chamber 43 into the duct 56. The rate of flow is dependent upon a variety of factors including the flowability of the material itself, the size of the opening 4817, the density and particle size of the matterial, the difference in pressure between the chamber 48 and feeding compartment 34, the distance the valve disk 60 is moved from its seated relation and the time interval that the disk is open. When the disks are in the position shown in FIG. 2, the material in the feeding compartment 34 cannot flow into the chamber 4-3 but the material accumulated in the chamber 43 flows out the opening 501; into the duct 56 and is transported in the duct to the desired location. The rate of the flow is dependent upon a variety of factors including the amount of material in the chamber when the disk 62 is open, the flowability of the material itself, the size. of the opening Sill), the size of the duct 55, the pressure differential between the chamber 48 and duct 56, the distance the valve disk 62 is moved from its seated relation and the time interval that the disk is open.

If it is desired to reduce the rate of flow of a given size mechanism, a cylindrical wall 61 can be inserted between the upper and lower valve disks 6!} and 62 as is shown in FIG. 10 of the drawing. The cylinder 61 decreases the effective volume of the chamber 48 and prevents a build-up of material between the valve disks for a given size chamber and given material can be obtained by varying the time intervals in the up and down positions. It has also been found that better flow is obtained by utilizing a high speed of valve movement limited, of course, so that inertia forces do not become great enough to be destructive to the mechanism. The feed mechanism can be utilized to feed materials into the duct 56 when the pressure in the duct is both below and above the pressure in the hopper 22 with good results.

If the pressure in the duct 56 is greater than in the hopper 22, a small amount of air will flow upward into the hopper during the up or down movement of the disks. However, the amount is small because of the rapid speed of movement of the disks and the compaction of the material over or under the disks between the seat forming a temporary seal. However, the majority of this air flow will take place at the path of least resistance which is to the left of the baffle 41 as viewed in FIG. 2 since there is little or no accumulation of material at this point because of the action of the bafile. This air then passes out through the front wall vent cloth 42b and the expanded metal screen 42a to the atmosphere. Some of the vibrations of the mechanism are transmitted to the hopper Z2 and feeding compartment 34 and this aids the material to flow freely as well as prevents bridging and buildup of materials. When the pressure in the duct 56 is less than in the hopper 22, the small amount of air flow into the duct similarily aids the materials to flow. The utilization of resilient valve disks alternately seating on generally conical seating surfaces provides a highly successful feeding mechanism that will handle even the grittiest and most abrasive material with a minimum of wear on the mechanism. Furthermore, it has been found that a vibratory feeder of this type can operate at much higher feed rates than other types of feeder mechanisms.

Furthermore, a larger range of feed rates for a variety of diiferent materials can be readily obtained by varying the time intervals that the disks are in the up and down positions. It is to be noted that the time in the up or in the down position does not necessarily have to be equal.

For normal operations the period of dwell in the up.

and down positions can be approximately equal. As an example, it was found that in feeding granular bentonite from atmospheric pressures into an air stream of 4 p.s.i.g., the dwell in the down position of secs. and in the up position of 2 secs. produced a high feed rate and that by extending the time interval in the down position the feed rate is decreased. Some materials feed best with a slow cycle while others work best at a rapid cycle. Valve movement average velocities in the range of 40 to 100 f.p.m. have been utilized to good advantage. Also the novel construction of the mechanism is practically self-cleaning and requires very little maintenance because of the vibration and the use of flexible disks alternately seating on substantially conical seats. For ease in moving the feeding mechanism from one place to another, a pair of rollers 57 shown in dotted lines in FIG. 2 may be provided.

In order to provide for the up and down reciprocation of the rod 64 and the valve disks, the upper end of the rod 64 is connected to a piston rod 66a of an air cylinder 66 by means of the flexible coupling 68. The coupling 63 allows the lower end of the rod 64 to be laterally flexible enough to provide good seating of the disks 69 and 62 and also serves to reduce the shock of the cylinder 66 when the valve disks seat. The cylinder 66 is mounted on the top wall 38 in axial alignment with the opening 46a in the bottom wall and the valve chamber 48.

One system of actuating the cylinder 66 to produce controlled movement of the rod 64 and alternate seating of the disks 66 and 62 is illustrated schematically in FIG. 3. This system is operated by compressed air and requires no electrical power and, hence, is useful in a variety of field locations where power is not readily available.

Compressed air from an air compressor or other source is connected to" the inlet line 'iflat the arrow A. The line 70 is provided with a regulator and pressure reducer valve 72 to regulate the pressure to the system and control the speed of movement of the piston in the cylinder 66. The inlet line 70 is connected'to the inlet port 74a of a sliding type 4-way reversing valve 74. The valve 74 is provided with a sliding valve member 76 having a plurality of different passages for directing the air flow to re- Verse the direction of movement of the piston rod 66a in the cylinder.

When the valve member 76 is positioned as shown in FIG. 1, compressed air from the inlet port 74a is directed to the upside end of the cylinder 66 through the line 78 causing the piston rod 66a to move rapidly upward, the speed of movement depending on the setting of the regulator valve 72. Air in the downside of the cylinder 66 is forced out through the line 89, a passage in the valve member 76, and out the exhaust port 74b to the atmosphere.

During this time, high pressure air from the line 78 is directed to the inside of the valve chamber 48 to aid in flushing the material out into the duct 56. A check valve 82 is provided to'prevent back flow of air and material into the system from the chamber 48 and a throttle valve 84 is provided to control the rate of air flow into the chamber 48 and consequently control to a certain extent the rate of feeding of the material from the chamber 48 into the duct 56. High pressure air is also directed from the line 78 through a throttling valve 86 into a cylinder 88 having a piston and rod 88a connected to one end of the slide member 76 of the valve 74. A check valve 96 is provided in parallel with the valve 86 so that air flow from the line 78 to the cylinder 88 can be controlled by regulation of the throttle valve 86. A cylinder 92 and piston and rod 92a are also provided at the other end of the valve 74 with the rod 92a being connected to the other end of the sliding valve member 76. The cylinder 92 is connected to the line through a check valve 94 and throttling valve 96. When the valve member 76 is positioned as shown in FIG. 3, air in the cylinder 92 can exhaust through both the check valve 94 and throttling valve 96, the line 86, and out through a passage in the valve member 76 and exhaust port 74b.

The valve 74 is of the type commonly referred to as the stick-slip type which requires a greater force to initially move the sliding member 76 than it requires to keep the member moving after it has started moving. Consequently, with the member 76 in the position shown in FIG. 3, the pressure in the cylinder 88 gradually builds up at a rate controlled by the setting of the throttle valve 86 until the pressure difference between the cylinder 88 and the cylinder 92 is sufiicient to cause the valve member 76 to slide rapidly downwardly to reverse the direction of air flow to the cylinder 66. 1

When this happens, high pressure air is directed to the line 8i) causing the piston rod 66a to move rapidly downward and seat the lower valve disk 62. The air in the lower end of the cylinder 66 passes through the line 78, through a passage in the valve member 76 and out the exhaust port 74b to the atmosphere. The high pressure air in the line 80 is then directed into the cylinder 92 at a rate controlled by the throttling valve 96 and air in the cylinder 83 is exhausted to atmosphere through both the check valve 96 and throttling valve 86 until the pressure difference between the cylinder 92 and the cylinder 88 is suflicient to overcome the sticking force in the Valve 74- and cause the valve member 76 to slide rapidly upward and reverse the pressure flow to the cylinder 66 and start another cycle of operation.

Thus, the control system illustrated in FIG. 3 provides a means for actuating the cylinder 66 in order to move the rod 64 up and down and alternately seat the valve disks 6t) and 62. The rate of movement of the rod and valve disks is easily controlled by the pressure regulator valve 72. The time interval during which the rod and valve .disks are'in the up position is readily controlled by the throttling valve 36 and the time interval in which the rod and valve disks are in the down position is controlled by the throttling valve 96. The throttling valve 84 controls the rate of material flow from the chamber 48 into the duct.

Another system for actuating the cylinder 66 to reciprocate the rod and valve disks is schematically illustrated in FIG. 4 of the drawing. In this system a solenoid controlled, spring return, 4-way air valve 105) is used to revise the air pressure flow to the cylinder 66. The valve hit is provided with a sliding valve member 1112 having a plurality of passageways therein and a return spring 13-4 which normally biases the member 162 in the down position. Air under pressure from an air compressor or other source is connected to an inlet line 1% at the arrow A. The line 196 is connected to an inlet port 1%.: of the valve 1% and a pressure regulator valve 72' is provided to control the inlet pressure and function similarly to the valve 72 of the system shown in FIG. 3. The high pressure air from the inlet port who goes through a passage in the sliding valve member 1&2 to the line 78 which is connected to the cylinder 66 to raise the rod and valve disks to the up position. High pressure air is also directed from the line 7 3' to the throttle valve 84' and check valve 82' which function in the same manner as described previously for the valves 82 and 84 of FIG. 3 and thence to the chamber 48 to flush it out. Air in the upper end of the cylinder 65 passes through the line 813', a passage in the sliding valve member 102 and out an exhaust port 1%]; of the valve 1%. The valve member 162 is provided with a rod 1ti2a of magnetic material. A solenoid coil 1% is connected when energized to exert a pull on the valve member 162a, pulling the sliding valve member 1% upward to the position shown in FIG. 4 against the force of the return spring 164. When the coil 166 is deenergized the spring 104 moves the member 102 downward so that the inlet port 1tltla is in communication with the line 81) and the exhaust port 100!) is in communica tion with the line 78. Thus, if an electrical power failure should occur, the valve member 102 would'move downward under the force of the spring 1114 directing high pressure air to the line 89 and move the rod and valve disks to the down position to shut off any material flow from the chamber 48 to duct 50. The coil 1% is energized and deenergized for controlled intervals of time by means of an electric power source (not shown) through the on-off switch 119, fuse 112 and timer 168.

Referring now to the timer 108, when the feeding device is to be placed in operation, the main switch 110 is operated to a closed condition so that a circuit is completed through a normally closed pair of contacts 114 in the timer 1% to energize the winding 106 of the solenoid. This shifts the valve assembly 160 to the position shown in FIG. 4 in which compressed air is applied to the lower end of the piston 66 to elevate the valve disks to the up position. The closure of the switch 110 also completes a circuit through a pair of normally closed contacts 116:: in a switch 116 in the timer 108 to complete an energizing circuit for a forward drive motor 113 included in the timer 103. hVhen the timer motor 118 is energized, cam means connected thereto are driven in a forward direction to initiate that timed interval that the valve assembly 101% is held in its operated condition.

After a predetermined period of time, the cam means driven by the motor 118 opens the normally'closed conacts 114 and 11601 and closes a pair of normally open contacts 1160 in the switch 116. The opening of the contacts 114 interrupts the energizing circuit for the winding 1% so that the compression spring 104 restores the valve assembly 1th) to its alternate condition in which compressed air is supplied to the upper end of the piston 56. This operates the valve disks to their alternate or down position. The opening of the contacts 116a terminates the encrgization of the forward drive motor 118, and the closure of the contacts 116i) energizes a reverse 8 drive motor 120 that also forms a part of the timer 108. The motor 120 drives the cam means in a reverse direction.

After a predetermined period of time, the cam means now being driven by the reverse driving motor 120 advances to a position in which the contacts 114 and 116a are again closed and the contacts 11611 are opened. The closed contacts 114 again energize the winding 1% to operate the valve assembly 1% to its illustrated position. The closing of the contacts 115a energizes the motor 113, and the opening of the contacts 115b stops the motor 12% Thus, the time intervals during which the valve disks are either in the up position or down position can be controlled by setting the timer 168 and a variety of desired time intervals can be easily obtained. The operation of the feeding device is terminated by opening the main switch 119.

Thus, the timer 1&8 energizes the solenoid coil 1% for an adjustable period of time causing the valve member 1112 to direct air pressure to the line 73 to move the rod and valve disks to the up position and remain there for the timed interval. The timer then deenergizes the solenoid and the spring 164- moves the valve member to the downward position directing high pressure to the line 83 to move the rod and valve to the down position for a timed interval until the solenoid 166 is again energized to repeat the cycle.

Referring nowv to FIGS. 5 and 6 of the drawings, there is illustrated another embodiment of the present invention having a ditferent valve chamber and valve disk arrangement. The material hopper and feeding compartment are essentially the same as shown in the embodiment of FIGS. 1 and 2 and have been given similar reference numerals where the parts are similar or identical.

The bottom wall 149 of the feeding compartment 34 is provided with a somewhat larger feed opening a which communicates with the upper end of a valve chamher 148. The upper end of the valve chamber 148 is provided with outwardly sloping walls forming a generally conical upper valve seating surface 148a. The upper end of the walls are terminated in a radial flange 151 which is attached to the bottom wall M0 of the feeding compartment 34 by means of the bolts 151a. A gasket 154 is interposed between the bottom wall of 140 and the flange 151 to provide a seal therebetween. The walls forming the lower portion of the chamber 148 taper outwardly to form a generally conical lower valve seating surface 15th:. The seating surfaces 143 and 1500: are joined together by a generally cylindrical middle portion 153 which is smaller in diameter than the valve disks 161i and 164. The lower end of the lower tapered seating surface 1513a forms an outlet opening 15% which communicates with the interior of the duct 56 by means of the cylindrical chamber extension 1480. The complete chamber 148 is formed ofan upper member 152 and a lower member 154. These members are joined together ad acent the mid-portion 153 of the chamber by means of the flange and bolt connection 156 and the gasket 158.

The upper valve disk 16%) and lower valve disk 162 are secured on the threaded valve rod 164 by means of the nuts and washers so that they may be adjusted and properly spaced so that they will seat alternately on the surfaces 148a and 15%, respectively, as the rod 164 is moved down and up. The upper end of the rod 164 is connected to the cylinder rod 56a of the cylinder 66 by means of the coupling 68 and actuating system as illustrated in FIGS. 3 and 4 and as previously described are utilized to provide the reciprocating movement desired.

It has been found that the embodiment of the invention illustrated in FIGS. 5 and 6 and just described works better'with certain materials and that the embodiment of FIGS. 1 to 3 works better with others. When the lower valve disks-152 is seated against the lower seating surface 1511a, as shown in FIG. 5, the flow of material in the valve chamber 143 to the duct 56 is stopped and material in the feeding compartment 34 flows into the chamber 14% around the upper valve disk 160 through the opening 149. Of course, the rate of this flow is dependent on the same factors, some of which were previously mentioned in connection with the first embodiment.

The rod 164 and valve disks 160 and 162 are then moved rapidly downward by the cylinder as under actuation of a system such as shown in FIG. 3 or 4 until the upper valve disk 16% is seated against the surface 148a closing off the flow into the chamber 148 from the feeding compartment 34. The lower valve disk 162 is en away from the seat and material flows from the chamber 148 into the duct 56 at a rate determined by many factors including the ones previously mentioned in connection with the first embodiment.

Air leakage between the feeding compartment 34, the valve chamber 148 and duct 56 during the up and down movements of the rod and valve disks is minimized by the rapid movement of the disks as well as compaction of the material above and below the disks. If the air pressure in chamber 148 is greater than it is in the feeding compartment 34 and hopper 22, a small amount of air will flow upward from the chamber into these areas. As before mentioned, the majority of this flow will take place to the left of the bafile 41 which is the path of least resistance and will then pass out to the atmosphere through the cotton vent cloth 42b and expanded metal screen 42a. By adjusting the intervals of time during which the valve disks remain in either the up or down position, the flow rate can be accurately controlled. Also, the disks can be moved at a high speed because of the cushioning action of the valve disks as they are seated alternately; Additionally, the vibrations caused by the rapid reciprocal movement of the valve mechanism aid in preventing materials from bridging or building up in the valve chamber itself, the feeding compartment, and the upper valve disk.

To aid in flushing the material into the duct 56 from the chamber 148, an air line is connected to the interior thereof in a manner shown in FIGS. 3 and 4 with the slight difference in connection in that the flushing line is connected to the line 8% or 3h instead of 78 or 78 so that the flushing air is directed into the chamber 148 when the rod and valve disks are in the down position, as illustrated in FIG. 6.

Referring now to the embodiments illustrated in FIGS. 7, 8 and 9, when it is necessary to feed material into a flow duct which is at a great pressure differential, either,

higher or lower than the pressure in the material hopper, it may be desirable to provide reciprocal valve mechanisms having three, four or more resilient valve disks.

FIG. 7 illustrates an embodiment having three resilient valve disks 260, 2&2 and 284 which are secured in concentric spaced apart relation on a reciprocating valve rod 206. The valve disks are secured on the rod in the proper spaced relation by means of the nuts and washers 2433 and be adjusted to provide for proper seating of the valve disks and to compensate for wear. The upper pair of disks 2th and 222 are positioned to alternately seat in an upper valve chamber 210 in a manner similar to that described in connection with the embodiment of FIGS. 1 and 2. The chamber 215) is provided with an internal generally conical upper seating surface 2212 upon which the disk Ztit) seats when the rod and valve mechanism is in the up position and is provided with a lower internal generally conical surface 214 upon which the valve disk 292 seats when the rod and valve mechanism is in the down position. The chamber 21% is provided with a generally cylindrical mid-portion 216 of greater diameter than the valve disks 2% and 2(32.

There is provided adjacent the lower end of the cham her 210 another chamber 218 which is similar in construction to the chamber 148 of FIGS. and 6. The

chamber 218 is provided with a generally cylindrical midportion 220 of a diameter smaller than the valve disks 202 and 2434. The portion 220 is joined at its upper end to the lower end of the seating surface 214 and the lower end of the chamber 218 is provided with an outwardly projecting generally conical lower seating surface 222 which forms a seating surface for the valve disk 204 when the valve mechanism is in the up position. The lower end of the seating surface 222 is joined to a generally cylindrical chamber 224 having a diameter greater than the valve disk 294 so the disk can move freely therein. The lower end of the chamber 224 communicates with the interior of a flow duct 56 so that material in the chamber 218 may enter the duct and be carried away by the air stream therein when the lower valve disk 204 is in the down position, as shown in FIG. 7. Thus, the upper chamber 210 with the valve disks 202 and 204 alternately seating against the surfaces 212 and 214 is similar in construction to the embodiment of FIGS. 1 and 2 and the lower chamber 218 with the valve disks 262 and 204 alternately seating against the surfaces 214 and 222, respectively, is similar in construction and operation to the embodiment of FIGS. 5 and 6. The upper end of the upper chamber 210 is connected to the lower end of a feeding compartment 234 attached to a material feed hopper 222 in a manner similat to that described in the preceding embodiments. The upper end of the rod 206 is connected to the end of a cylinder rod 66a of an air cylinder 66 through a coupling $8 in order to provide reciprocating movement of the rod and valve disks. A system for actuating the cylinder 66 similar to those of FIGS. 3 and 4 may be utilized to control the actuation of the rod and valve disks.

When the rod and valve disks are in the down position of FIG. 7, material in the hopper 222 and feeding compartment 234 flows into the upper chamber 210 around the disk 2% but cannot flow from the chamber 210 into the chamber 218 because the valve disk 202 is seated on the surface 214. Material in the lower chamber 218 feeds into the duct 56 around the valve disk 204 which is below the seating surface 222 in this position.

The rod and valve disks are then moved to the up position rapidly and the upper disk 2% seats on the surface 212 shutting off the fiow of material into the upper chamber 21% from the feed compartment 234 and also the lower disk 204 seats against the surface 222 shutting off the flow of material into the duct 56 from the lower chamber 218. Since the valve disk 202 is not seated on the surface 214 at this time, material in the chamber 210 flows into the lower chamber 218.

The flow rates of material from the feeding compartment 234 into the upper chamber 210, and from this chamber into the lower chamber 218 and then into the duct 56 for transportation in the air stream are governed by various factors including those mentioned in discussin. the previous embodiments.

In applications where very light material is being fed and high pressure differentials are involved, either positive or negative, between the material hopper and the flow duct, it has been found that the embodiment illustrated in FIG. 7 works very well. Problems in feeding low density material into or out of high pressure environments are encountered because of the amount of air flow from high to low pressure when the valve disks are moving, and this is sufficient to virtually stop the flow, if in a reverse direction, and to rapidly dump a large quantity of material in the system with consequent clogging if the air flow is the same direction as the material fiow.

For this reason, the use of the chamber 210 in series with the chamber 218 in a single feed mechanism provides a means for providing a series of stepped pressure gradients in which the pressure differential across any one of the valve disks is reduced so that the amount of air flow around the disk during its movement is not objectiona le. Furthermore, with rapid movement of the valve disks, air in the duct 56, at high pressure for instance, does not have time enough to reach the upper disk 2% before it seats and then after the disks are seated the pressure differential in the chamber 210 bleeds off slowly into the compartment 234- without greatly reducing the downfiow of material as it would if only a single valve chamber and pair of valve disks were used. In effect, the average pressures in the chambers 21% and 218 are between the pressures in the duct 56and feeding compartment 234 and the pressure difference between any two adjacent areas in the feeding path of the material is smaller than in the case of a single feed chamber between the duct and hopper where a high pressure differential is necessary.

Referring now to FIGS. 8 and 9, where very high pressure differentials are required between the hoppers 322 and feeding compartments 334 and the flow duct as, three valve chambers 348A, 3483 and 14-8 have beenutilized in series to further reduce the pressure differential between the adjacent areas in the path of material flow. In the embodiment of FIG. 8, four valve disks 36%), 362, 364 and 366 are attached to a single rod 368 which is connected to the piston rod 66a of the actuating cylinder 66 by the coupling as. The chamber 343A with the valve disks 360 and 362 and the chamber 3483 with valve disks 364 and 366 both are similar in operation and construction to the chamber 48 and valve disks 6% and 62 of the embodiment illustrated in FIGS. 1 and 2 and previously described. The chamber 148 with associated valve disks 362 and 36 3 is similar in operation and construction to the chamber 14-8 and disks 169 and 162 of the embodiment illustrated in FIGS. and 6. The cylinder 66 may be actuated by a system of the type illustrated in FIG. 3 or 4 and previously described in the specification.

When the rod 36313 and valve disks are in the down position shown in FIG. 8, material flows from the feeding compartment 334 into the upper chamber 343A. Material cannot flow from this chamber into the middle chamber 148 because the valve disk 362 is seated. Material flows from the chamber 148 into the lower chamber 3483 but cannot flow therefrom into the duct.

When the rod 358 is moved to the up position by the cylinder and actuating system, material flows from the feeding compartment 334 into the upper chamber 348A, but material cannot flow from this chamber into the middle chamber 148. Material cannot flow from the chamber 148 into the lower chamber 3483, but does flow from the chamber 3483 into the duct. 56 for transportation in the air stream.

By placing in effect three valve chambers with valve disks which alternately seat therewith in series between the feeding compartment and the duct, it is possible to successfully feed very fine or light materials from a region of very high to very low pressure or vice versa since the pressure differential between any two adjacent areas along the path of material flow is reduced to a workable level. It has also been. found that when operating at high pressure differentials between adjacent chambers that longer periods of dwell with the valve disks in the seated position are desirable when the pressure differential is counter to the direction of material flow because of a slightly longer time required to equalize the pressure before material effectively starts to flow under the effect of gravity. The converse, of course, is true when the pressure differential is with the direction of material flow to prevent dumping of large quantities of'material rapidly into the system which might momentarily clog it up.

The embodiment of FIG. 9 is similar to FIG. 8 except that the lower valve disks 364 and 366 are connected to a separate rod 368A which is actuated by a separate air cylinder 56A. This construction allows greater flexibility of control of the mechanism since two separate actuation systems can be synchronized to operate the cylinders 66 and 66A.

There is illustrated in FIG. 11 another embodiment of a system for feeding and transporting materials which system is indicated generally by the reference numeral iP).'This system is especially well suited for use with low pressures and is relatively simple in construction, thus making it economical-to manufacture and install. The system 4% includes a material hopper 482 into which quantities of sand or other material 404 to be transported are dumped. The hopper 402 has sloping walls converging inwardly to form an outlet 4% at the bottom leading to a feed chute res which is connected to the outlet in any suitable manner such as by welding or by a flange and bolt construction as illustrated. The lower end of the feed chute 4% angularly intersects with a feeder unit indicated generally by the numeral 419.

The feeder unit 41?; is preferably constructed of several sections of round pipe and comprises an upper section 412, an intermediate section 414, and a lower section 416. The upper section is provided with a top plate 418 for mounting an actuating cylinder 429 which has a piston rod 422 and is similar to the cylinder 55 previously described and which may be controlled by a control system such as illustrated in FIG. 3 or FIG. 4 and described above. The lower end of the section 412 is provided with a flange 422 for joining this section to the intermediate section 414 by means of bolts 424.

The intermediate section 414 is provided with upper and lower end flanges 426 and 423, respectively, with the upper flange 426 facing the flange 422 of the upper section 412. Between these two flanges there is provided an orifice plate 439 which may be constructed of steel plate and has a central flow opening or orifice 432 defined therein.

A similar orifice plate 434 having a central flow opening or orifice is positioned between the lower end flange 428 of the intermediate section 414 and an upper end of the lower section 416. These two flanges and the orifice plate 434 are held together by suitable means such as bolts 441i and the lower end of the lower section 416 is provided with a lower end flange 442 which is suitably attached, as by bolts 44-8, to the top plate 444 of a lower hopper 446. The top plate 444 is provided with an opening 450 aligned with the lower section 416 in order to allow material to flow into the hopper 446.

The feeder unit 41% is provided with a reciprocal valve mechanism actuated by the cylinder rod 429a comprising an upper valve disk 452 and a lower valve disk 454. These disks are preferably of resilientmaterial such as rubher or the like and are positioned in spaced apart relation on a threaded valve rod 455 which is attached to the end of the cylinder rod 329a by means of a flexible coupling 458. The disks are secured on the rod 456 by means of nuts and washers in a conventional manner. In order to prevent a large build up of material on the upper surface of the valve disks, there are provided conically shaped collars 460 which are positioned above the disks.

The low er hopper 446 is provided with sloping side walls formmg an opennig 462 at the bottom of the hopper to which a vertically extending nozzle 464 is connected. The nozzle 464 is connected to a source of air pressure such as a blower 466 or the like through a pipe 468 and elbow 4-70. Centrally positioned within the hopper Add and coaxial with the nozzle 464 there is provided a vertically positioned, upwardly extending flow duct 472 for transporting material to a desired location. An end collar 474 at the lower end of the flow duct 472 has tapered inner walls and is spaced vertically upward from the nozzle 464 so that high velocity air from the nozzle entrains the material in the hopper and carries it upward in the flow duct to be transported to the desired location.

In operation of the system, the material 40-4 in the hopper 4%2 flows downwardly through the feed chute 488 into the upper section 412 of the feeding device 410 and around the valve disk 452 through the orifice 432 into the intermediate section 414. The rate and amount of flow is dependent on many factors including the flowability of the material, the level or amount of material in the hopper, the size of the feed chute, upper section, valve disk and orifice diameter, and the amount and velocity of upward travel and duration of dwell in the upper position of the upper valve disk. When the valve mechanism moves downwardly the upper valve disk 452 seats on the orifice plate 439 to prevent flow from the upper section 412 to the intermediate section 414 and, at the same time, the lower disk 459 moves downwardly away from seating engagement with the lower orifice plate 434 to permit the material in the intermediate section to fiow into the lower hopper 446 for transportation in the air stream. This rate of flow is likewise dependent on several factors as discussed above.

The material in the hopper 446 flows toward the bottom of the hopper where it is picked up by the air stream from the nozzle 464- and is carried up the flow duct 472. The rate of flow again is dependent on many factors including the particle size, density and flowability of the material, the amount of air pressure available from the blower, the distance between the lower collar 474 and the nozzle, and the shape of the internal surface of the collar and nozzle.

When it is desired to stop the flow, the feeder mechanism 416' is shut down with its valve disks in the position shown in FIG. 11 and the material remaining in the hopper 445 is carried out through the flow duct 472 at which time the blower 466 is shut down. When it is desired to start the flow of material, the feeder mechanism is again placed in operation and the blower is started.

As was previously discussed in connection with other embodiments the rate of flow through the feed mechanisrn can be accurately controlled by adjusting the time periods of dwell in the. up and down positions of the valve mechanism. The use of standard round pipe and flat orifice plates makes the feeding mechanism simple and economical to construct and, while it does not possess some of the advantages of the other embodiments, the arrangement shown in FIG. 11 will work well with relatively free flowing material such as sand. Also, orifice plates having various size openings can easily and rapidly be installed in the feeding mechanism to obtain the desired flow rate. Air flow from the lower hopper 4-46 into the feeding mechanism when the valve disk are in transit between seating is of little consequence and is minimized by utilizing high velocity movement of the valve mechanism.

While there have been shown and described several embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the invention in its broader aspects, and it is, therefore, contemplated in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A feeding unit for feeding material from a material containing hopper into a flow duct having a moving fluid stream therein, said unit comprising a first valve chamber having an inlet opening at its upper end adapted for communiaction with said hopper and an outlet opening at its lower end, said chamber including an upper, annular, generally conical seating surface encircling said inlet opening and a lower, annular, generally conical sea ing surface encircling said lower outlet, a first movable valve member disposed in said first valve chamber including upper and lower generally cylindrical, resilient valve disks in spaced apart concentric relation to one annother and movable on an upward stroke to seat said upper disk against said upper seating surface when said lower disk is away from said lower seating surface and on a downward stroke to seat said lower disk against said lower seating surface when said upper disk is away from l4 said upper seating surface, rod means having an outer end and a free end extending into said first chamber through one of said openings in axial alignment therewith including means for securing said disks thereon in said spaced apart relation, means externally of said chamber connected to the outer end of said rod means for reciprocally moving said first valve member to effect alternate seating of said disks against their respective seating surfaces for predetermined selected periods of time, a second valve chamber having a seat therein and an inlet end in communication with said outlet opening and an outlet end adapted for communication with said flow duct, a second valve member disposed in said second valve chamber movableinto engagement with and away from said seat and means for moving said. second valve member to engage said seat for selective predetermined time intervals.

2. Apparatus for feeding granular material into a fluid conduit containing a moving fluid stream, said apparatus comprising a generally vertically extending valve chamber having a lower discharge outlet in communication with said conduit and also having a pair of vertically spaced apart, gradually tapering, elongated, generally conical upper and lower valve seating surfaces in concen tric arrangement about a central vertical axis of the chamber, a supply chamber disposed vertically above said valve chamber, dividing means for separating said supply.

chamber into a hopper section for containing a supply of granular material and a feeding chamber communicating with said hopper section through an opening in-said dividing means, said feeding chamber being'disposed above and having a lower discharge outlet in communication with said valve chamber, rod means extending downwardly from said feeding chamber through the outlet thereof and having a free end reciprocally movable along the central axis of said valve chamber, upper and lower generally flat, substantially cylindrical, resilient valve disks arranged in vertically spaced-apart relation on the free end of said rod means and movable therewith transversely of said central axis for alternate self-aligned seating of the disks against the gradually tapering portions of the respective seating surfaces upon reciprocal movement of said rod means, a fluid cylinder mounted on said feeding chamber above the outlet and coaxial with the central axis of said valve chamber, piston means reciprocally movable in said cylinder and operatively connected with the upper end of said rod means, and means for selectively supplying pressurized fluid to said cylinder to reciprocate the piston means.

3. Apparatus for feeding granular material into .a fluid conduit containing a moving fluid stream, said apparatus comprising a generally vertically extending valve chamber having a lower discharge outlet in communication with said conduit and also having a pair of vertically spaced apart, gradually tapering, elongate-d, generally conical upper and lower valve seating surfaces in concentric arrangement about a central vertical axis of the chamber, a supply chamber disposed vertically above said valve chamber, dividing means for separating said supply chamber into a hopper section for containing a supply of granular material and a feeding chamber communicating with said hopper section through an opening in said dividing means, said feeding chamber being disposed above and having a. lower discharge outlet in communication with said valve chamber, rod means extending downwardly from said feeding chamber through th outlet thereof and having a free end reciprocally movable along the central axis of a said valve chamber, upper and lower generally flat, substantially cylindrical, resilient valve disks arranged in vertically spaced-apart relation on the free end of said rod means for alternate seating against the gradually tapering conical portions of the respective seating surfaces upon reciprocal movement of said rod means, a fluid cylinder mounted on said feeding chamber above the outlet and coaxial with the central axis of said valve chamber, piston :means in said cylinder reciprocally movable therein, means for selectively supplying pressurized fluid to said cylinder to reciprocate the piston means, and flexible coupling means interconnecting said rod means and said piston means for permitting limited movements of the free end of said rod vmeans transversely of said central axis during reciprocal movement thereof to effect self-aligned seating of the valve disks with their respective conical seating surf-aces.

4. Apparatus as defined in claim 3'wherein said valve disks are detachably and adjustably secured on the free end of said rod means to permit adjustment of the disks with respect to the seating surfaces and to facilitate replacement of the disks.

5. Apparatus as defined in claim 3 wherein said feeding chamber is rovided with vent means for venting the chamber to atmospheric pressure while preventing the loss of the granular material to the atmosphere.

6. Apparatus as defined in claim 3 wherein said dividing means includes a vertical Wall having said opening therein and gate means movable with respect to said opening for maintaining the material in said feeding chamber at a selected level.

7. Apparatus for feeding granular material into a fluid conduit containing a moving fluid stream, said apparatus comprising a generally vertically extending valve chamber having a lower discharge outlet in communication with said conduit and also having a pair of vertically spaced apart gradually tapering, elongated, generally conical upper and lower valve seating surfaces in concentric arrangement about a central vertical axis of the chamber, a suply chamber disposed vertically above said valve chamber for containing a supply of granular material and having a lower discharge outlet in communication with said valve chamber, rod means extending downwardly from said supply chamber through the outlet thereof and having a free end reciprocally movable along the central axis of said valve chamber, upper and lower generally flat, substantially cylindrical, resilient valve disks arranged in vertically spaced-apart relation on the free end of said rod means for alternate seating against the gradually tapering portions of the respective seating surfaces upon reciprocal movement of said rod means, a fluid cylinder mounted on said supply chamber above the outlet and coaxial with the central axis of said valve chamber, piston means in said cylinder reciprocally movable therein, means for selectively supplying pressurized fluid to said cylinder to reciprocate the piston means, and flexible coupling means interconnecting said rod means and said piston means for permitting limited movements of the free end of said rod means transversely of said central axis during Al. reciprocal movement thereof to effect self-aligned seating of the valve disks with their respective conical seating surfaces.

8. Apparatus as defined in claim 7 wherein said fluid supplying means includes a reversing valve having a sliding valve elementmovable between a first position for supplying pressurized fluid through a first line connected to one end of said cylinder while permitting the exhaust of fluid through a second line connected to an opposite end of said cylinder and a second position for supplying pressurized fluid to said second line while permitting exhaust of fluid from said first line, and means for moving said valve element between said positions at selected time intervals.

9. Apparatus as defined in claim 8 wherein said last mentioned means includes a pair of fluid operated actuators disposed on opposite ends of said reversing valve and connected to said valve element and adjustable throttling means interconnecting each. of said actuators to a respective one of said lines to supply controlled amounts of fluid to said actuators from said lines to reciprocate said valve element.

10. Apparatus as defined in claim 8 wherein said last mentioned means comprises solenoid means operatively connected to move said valve element when energized from said first to said second ositions, spring means for biasing said element against said solenoid means toward said first position, and electric timer means for energizing and deenergizing said solenoid means for adjustable preselected time intervals.

11. Apparatus as defined in claim 8 wherein a flushing conduit is interconnected between one of said lines and 'said valve chamber for supplying flushing fluid to flush material from said valve chamber into said fluid conduit during the period when said upper valve disk is seated against the upper seating surface.

References Cited by the Examiner UNITED STATES PATENTS 799,808 9/05 Thompson 302 898,012 9/08 Shannon 214-36 1,482,677 2/24 Dunten 2l4-l7.4 2,723,057 ill/55 Golden 30255 2,943,890 7/60 Hrabovszky 302-l4 FOREIGN PATENTS 1,094,662 12/60 Germany.

834,052 5/60 Great Britain.

SAMUEL F, COLEMAN, Primary Examiner.

ANDRES H. NIELSEN, Examiner. 

1. A FEEDING UNIT FOR FEEDING MATERIAL FROM A MATERIAL CONTAINING HOPPER INTO A FLOW DUCT HAVING A MOVING FLUID STREAM THERIN, SAID UNIT COMPRISING A FIRST VALVE CHAMBER HAVING AN INLET OPENING AT ITS UPPER END ADAPTED FOR COMMUNICATION WITH SAID HOPPER AND AN OUTLET OPENING AT ITS LOWER END, SAID CHAMBER INCLUDING AN UPPER, ANNULAR, GENERALLY CONICAL SEATING SURFACE ENCIRCLING SAID INLET OPENING AND A LOWER, ANNULAR, GENERALLY CONICAL SEAT ING SURFACE ENCIRCLING SAID LOWER OUTLET, A FIRST MOVABLE VALVE MEMBER DISPOSED IN SAID FIRST VALVE CHAMBER INCLUDING UPPER AND LOWER GENERALLY CYLINDRICAL, RESILIENT VALVE DISKS IN SPACED APART CONCENTRIC RELATION TO ONE ANNOTHER AND MOVABLE ON AN UPWARD STROKE TO SEAT SAID UPPER DISK IS AWAY FROM SAID LOWER SEATING SURFACE WHEN SAID LOWER DISK IS AWAY FROM SAID LOWER SEATING SURFACE AND ON A DOWNWARD STROKE TO SEAT SAID LOWER DISK AGAINST SAID LOWER SEATING SURFACE WHEN SAID UPPER DISK IS AWAY FROM SAID UPER SEATING SURFACE, ROD MEANS HAVING AN OUTER END AND A FREE END EXTENDING INTO SAID FIRST CHAMBER THROUGH ONE OF SAID OPENINGS IN AXIAL ALIGNMENT THEREWITH INCLUDING MEANS FOR SECURING SAID DISKS THEREON IN SAID SPACED APART RELATION, MEANS EXTERNALLY OF SAID CHAMBER CONNECTED TO THE OUTER END OF SAID ROD MEANS FOR RECIPROCALLY MOVING SAID FIRST VALVE MEMBER TO EFFECT ALTERNATE SEATING OF SAID DISKS AGAINST THEIR RESPECTIVE SETING SURFACES FOR PREDETERMINED SELECTED PERIODS OF TIME, A SECOND VALVE CHAMBER HAVING A SEAT THERIN AND AN INLET END IN COMMUNICATION WITH SAID OUTLET OPENING AND AN OUTLET END ADAPTED FOR COMMUNICATION WITH SAID FLOW DUCT, A SECOND VALVE MEMBER DISPOSED IN SAID SECOND VALVE CHAMBER MOVABLE INTO ENGAGEMENT WITH AND AWAY FROM SAID SEAT AND MEANS FOR MOVING SAID SECOND VALVE MEMBER TO ENGAGE SAID FOR SELECTIVE PREDETERMINED TIME INTERVALS. 